The present invention relates generally to vacuum cleaners for use in cleaning carpets and other flooring materials in buildings and, more particularly, to a vacuum sweeper that incorporates a magnetic flux field to disrupt the static attraction of dust particles to carpet fibers.
Vacuum sweepers have been in use for many decades for the cleaning of carpets and other flooring materials in houses, businesses and other buildings. A conventional vacuum sweeper utilizes a fan to create a air flow through the structure of the sweeper and create a slight vacuum at the cleaning head to urge dust and other debris upwardly through the cleaning head into a collection system, typically a bag or other container surrounding a filter to dislodge the dust, dirt and other debris from the flow of air through the vacuum cleaner structure. Typically, the cleaner head incorporates a rotating brush beater that agitates the carpet fibers to try to separate the dust and dirt from the carpet fibers and allow the material to enter the air flow.
Present vacuum cleaners have been incorporating modern filtration systems, including hepa filters and micro-filters to capture smaller particles, such as allergens, bacteria and mold spores that may be found in the air flow through the structure of the vacuum cleaner. However, present cleaning heads are not very capable of removing such small particles from carpet fibers due to a static attraction between opposite electrical charges on the particle and the carpet fiber. In an effort to effect a separation of these small statically charged particles from the carpet fibers, modern cleaning heads have increased suction and more aggressive beater assemblies.
The separation of these small statically charged particles has been the focus of some patent activity in which an ion generator is placed on the cleaning head of a vacuum sweeper to either neutralize or eliminate the static attraction between the small particles and the carpet fiber to which the particle is engaged. Elimination of the static charges on the particles is the intent of the introduction of electrostatic charges from the cleaning head. In U.S. Pat. No. 2,280,751, issued to H. L. Davis on Apr. 21, 1942, the vacuum cleaner nozzle is provided with a smooth hard di-electric material that will generate an electrostatic charge when rubbed across the surface of the carpet. In U.S. Pat. No. 3,355,755, issued to J. R. Brooks on Dec. 5, 1967, a piezo-electric electrostatic brush having a conductor proximate to the dust cavity within the arrangement of bristles. In U.S. Pat. No. 4,197,610, issued to H. W. Schneider on Apr. 15, 1980, the housing surrounding the brush beater is grounded electrically to attract dirt particles that might be clinging to the brushes. In U.S. Pat. No. 4,715,086, issued to R. H. Johanson on Dec. 29, 1987, and in U.S. Pat. No. 4,866,565, issued to C. C. Wray on Sep. 12, 1989, electrostatic charges that may have accumulated on the wand during operation of the cleaning head can be dissipated.
Other attempts to neutralize the static attraction between the small particles and the carpet fibers involve ion generators, which require substantial voltages and potential danger. In U.S. Pat. No. 5,920,954. issued to R. Sepponen on Jul. 13, 1999, the vacuum cleaner is provided with an ionization electrode coupled to a generator of up to 10,000 volts of electricity. Although the current is low, the voltage is extremely high in order to generate the ion flow. The power required to generate such an ion flow is impractical for household vacuum sweepers and potentially dangerous to the operator. In U.S. Pat. No. 6,199,244, issued to S. Hilgers on Mar. 13, 2001, a generator is provided on the cleaning head to generate up to 20,000 volts of electricity in order to place an electrostatic charge on the base plate of the cleaning head.
In U.S. Pat. No. 4,728,942, issued to J. F. 1. England on Mar. 1, 1988, a magnet is used in the core of the brush beater to generate an electrical current when the brush beater is rotating that powers a light-emitting diode to indicate that the brush beater is actually rotating. The England patent does not teach the induction of a magnetic flux to disrupt the static charges on small particles in the carpet being cleaned. In U.S. Pat. No. 5,027,469, issued to H. Toyoshima, et al on Jul. 2, 1991, magnets are placed at various places in a vacuum sweeper to attract ferrous dust particles to prevent attraction thereof to the rotor and stator of the sweeper motor, thus increasing the life of the motor. The Toyoshima patent does not contain any teachings for the creation of a magnetic flux field that will disrupt the static attraction between small particles and carpet fibers. In a related teaching in U.S. Pat. No. 2,590,152, issued to J. P. Buckley on Mar. 25, 1952, a sterilizing ultraviolet generator is mounted in the cleaning head of a vacuum sweeper to destroy germs and bacteria in the carpet during operation thereof over the surface of the flooring.
The use of a magnetic flux field to disrupt the static attraction of small dust particles to plastic particles and the like is taught in U.S. Pat. No. 5,035,331, issued to Jerome I. Paulson on Jul. 30, 1991, in the form of a dedusting apparatus for plastic particles. In this Paulson patent, the plastic pellets are fed through a housing where air is blown through the pellets to remove the dust particles from the pellets. The small dust particles, however, will continue to cling to the pellets due to opposite static charges and the resulting attraction therebetween. This static attraction is disrupted by the magnetic flux field to enable the air current to remove the small dust particles from the pellets. Such technology is highly effective in removing dust particles as small as 0.001 microns, which is the general size of pollen and bacteria.
Accordingly, it would be desirable to provide a vacuum sweeper cleaning head with a magnetic flux generator to be effective in disrupting the static attraction between small particles clinging to carpet fibers as the cleaning head is passed over the carpet to effect a cleaning thereof. The increased effectiveness is dislodging small particles from carpet will result in an effective utilization of current filtration technology and the removal of bacterial and allergens from the carpet.